Getting the maximum power and channels on the RTL8187 WLAN wifi card

Reference: http://ubuntuforums.org/archive/index.php/t-1814516.html

Because of your local areas regulations, the operating systems will limit the power and channels based your location rules.

Some locations in the world have no rules on power and channels.

If you want maximum power and channels do this:

sudo iw reg set BO
sudo iwconfig wlan1 txpower 30

Remember to heatsink the RTL8187 so it does not get fried by the power increase.

To check if the change was successful:
sudo iw reg get

You should see the BO region set.


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Creating cheap custom power transformers by reusing a microwave oven transformer

Microwave oven transformers can easily be found discarded and reused to make a powerful custom transformer.  The ability to easily reuse the transformer comes from the primary and secondary windings being physically isolated from each other on the metal core.

The aim is to remove the secondary windings as cleanly as possible and wind a custom winding using enameled wire.  In my case for every one loop around the core gets one volt, the thicker the wire, the more current that can be supplied.

There are three windings on a microwave transformer, one primary and two secondaries.  In the pictures below, the primary is on the bottom and the secondaries are on the top.
The primary has hundreds of turns of thicker wire, do not modify this, keep it pristine.
The high voltage secondary, with thousands of turns of fine wire, we do not need this.
The six volt filament winding made from cloth insulated wire, we do not need this.

Removing the secondary is relatively easy. 

• Clamp the transformer in a vice and using a hacksaw, cut one end of the secondary off.  Be careful that the saw does not cut into the primary at the end and try to avoid cutting the paper inner paper insulator.
• Spray penetrating oil into the exposed wire in the transformer, this will help in the next stage.
• Using a large drift and hammer, bash out the rest of the wire a bit from both sides at a time until it comes out like a horseshoe.  If the drift is too small, it will compress the wire and make it impossible to remove easily.
• Once removed, clean all metal filings and make sure that the mylar paper insulator is intact, repair using insulating tape if required.  You do not want exposed metal cutting into the wire while winding.
• Now using enameled wire, rewind to your own specifications.  The image below is a 4 volt ugly monster with several windings in parallel.

Remember that this transformer will hum like a microwave when in use.  It will draw lots of power. 
It will require some kind of forced air cooling to keep it happy.  Reuse the microwave fan...
Don't attempt to take the laminations apart.  They are often welded. 
Best to source a transformer from a larger microwave oven, bigger = more power.


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Tower LCDI 30386-0 Safety Switch Disassembled Pictures

Pictures inside another safety switch, this time it is a American 110 volt one.  I found it weird that the main power cables were braided. WTF.

This one is activated using mechanical means and using discrete components.

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How to make a DIY Dvorak keyboard

Ever since learning that the QWERTY layout was invented by some clown to stop mega fast typing, I have been angered by said layout.

The Dvorak layout was invented to lessen typing fatigue as it is optimised for the English language.  

I decided to hack a USB QWERTY keyboard and make it Dvorak, it's easy!

First get a USB keyboard, you may want to try a used cheap one to practice on.

Then using a screwdriver, lever out all the letter keys, and some of the symbol keys as shown in the picture.

Next, plug in the naked keyboard and change the keyboard layout in your operating system to Dvorak.  For Ubuntu it is in system>preferences>keyboard.

I used a pencil to press each key switch to verify which letter went where.  This was easier than transposing the layout from a picture.

All done and ready to go.

Typing the first sentence too like 10 minutes, it felt so different.

Typing in the Dvorak layout is a bit different, all the keys for most words feel closer together, i.e the fingers don't have to travel as far to write most words.  This means more efficient typing in the long run.

 
I may try the One Handed Dvorak layout next, optimised for eating a sandwich while typing.